Nail clippers

ABSTRACT

The nail clipper contains a pair of blade bodies each having a cutting edge, a lever to be operated for bringing the cutting edges of the blade bodies into press contact with each other and a supporting shaft for linking the lever to the blade bodies; the cutting edges of the blade bodies being brought into press contact with each other by pressing the blade bodies with the lever against resilience of the blade bodies. The nail clipper is provided with bosses formed either on the lever or on the supporting shaft, so as to allow the supporting shaft to pivotally support the lever; and grooves formed on the rest of the supporting shaft and the lever, with which the bosses are engaged. Each groove has a mouth portion through which the boss is engaged and disengaged, a guiding portion capable of pivotally supporting the boss, and a connecting portion connecting the mouth portion and the guiding portion to each other. The groove has a pair of side wall surfaces opposing each other in the mouth portion, connecting portion and guiding portion and also a bottom surface connecting the side wall surfaces to each other.

This application claims the benefit of International Patent ApplicationNo. PCT/JP01/09925 filed on Nov. 13, 2001.

BACKGROUND OF THE INVENTION

The present invention relates to nail clippers.

A conventional nail clipper, for example, as shown in JapaneseUnexamined Utility Model Publication No. Sho 61-82502 has a supportingshaft which is notched to form a bearing hole, and a connecting pinattached to a lever is inserted to the bearing hole. In this nailclipper, although the lever can be incorporated into the supportingshaft easily by virtue of the bearing hole opening to the periphery ofthe shaft, this configuration per se involves problems that theconnecting pin of the lever easily slips off the bearing hole of thesupporting shaft and that the strength of the portion of the supportingshaft around the bearing hole is lowered. In addition, it is troublesometo form a supporting shaft having such a shape of bearing hole asdescribed above.

It is an objective of the present invention to provide nail clippers,capable of facilitating incorporation of a lever, ensuring bearing ofthe lever and enhancing the strength of the supporting section. It isanother objective of the present invention to provide a nail clipperwhose supporting shaft can be molded easily.

BRIEF SUMMARY OF THE INVENTION

In order to attain the objectives as described above, the nail clipperaccording to one aspect of the present invention contains a pair ofblade bodies each having a cutting edge, a lever to be operated forbringing the cutting edges of the blade bodies into press contact witheach other and a supporting shaft for linking the lever to the bladebodies. The cutting edges of the blade bodies are adapted to be broughtinto press contact with each other by pressing the blade bodies with thelever against resilience of the blade bodies. The nail clipper isprovided with a boss formed either on the lever or on the supportingshaft so as to allow the supporting shaft to pivotally support thelever, and a groove formed on the rest of the supporting shaft and thelever, with which the boss is engaged. The groove has a mouth portionthrough which the boss is engaged and disengaged, a guiding portioncapable of pivotally supporting the boss, and a connecting portionconnecting the mouth portion and the guiding portion to each other.Further, the groove has a pair of side wall surfaces opposing each otherin the mouth portion, connecting portion and guiding portion and also abottom surface connecting the side wall surfaces to each other.

The nail clipper according to another embodiment contains an upper bladebody having an upper cutting edge; a lower blade body having a lowercutting edge opposed to the upper cutting edge; a supporting shaftinserted to the blade bodies near the cutting edges respectively, alower end portion of the supporting shaft being engaged with the lowerblade body to be locked therewith, while an upper end portion of thesupporting shaft protrudes upward through the upper blade body; and alever having a first supporting section; the first supporting sectionbeing linked on the upper blade body to a second supporting sectionprovided at an upper end portion of the supporting shaft; wherein thecutting edges of the blade bodies are brought into press contact witheach other by pressing the upper blade body with the lever againstresilience of the upper and lower blade bodies. In this nail clipper,either the first supporting section of the lever or the secondsupporting section of the supporting shaft is a boss, while the othersupporting section is a groove, with which the boss is engaged. Thegroove contains a mouth portion through which the boss is engaged anddisengaged, a guiding portion capable of pivotally supporting the boss,and a connecting portion connecting the mouth portion and the guidingportion to each other. The groove has a pair of side wall surfacesopposing each other in the mouth portion, connecting portion and guidingportion and also a bottom surface connecting the side wall surfaces toeach other.

The nail clipper according another embodiment contains an upper bladebody having an upper cutting edge; a lower blade body having a lowercutting edge opposed to the upper cutting edge; a supporting shaftinserted to the blade bodies near the cutting edges respectively, alower end portion of the supporting shaft being engaged with the lowerblade body, while an upper end portion of the supporting shaft protrudesupward through the upper blade body; a lever having a pair of supportingarms; the upper end portion of the supporting shaft being inserted onthe upper blade body to a bearing recess defined between the supportingarms of the lever; a first supporting section provided in the supportingarms; and a second supporting section provided at the upper end portionof the supporting shaft; the first and second supporting sections beinglinked to each other; wherein the upper cutting edge and the lowercutting edge are brought into press contact with each other by pressingthe upper blade body with the lever against resilience of the upper andlower blade bodies. In this nail clipper, either the first supportingsection of the lever or the second supporting section of the supportingshaft is a pair of bosses opposing each other, and the other supportingsection is a pair of grooves, with which the bosses are engagedrespectively. Each groove has a mouth portion through which the boss isengaged and disengaged, a guiding portion capable of pivotallysupporting the boss, and a connecting portion connecting the mouthportion and the guiding portion to each other. Each groove has a pair ofside wall surfaces opposing each other in the mouth portion, connectingportion and guiding portion and also a bottom surface connecting theside wall surfaces to each other.

The nail clipper according to another embodiment contains an upper bladebody having an upper cutting edge; a lower blade body having a lowercutting edge opposed to the upper cutting edge; a supporting shaftinserted to the blade bodies near the cutting edges respectively, alower end portion of the supporting shaft being engaged with the lowerblade body to be locked therewith, while an upper end portion of thesupporting shaft protrudes upward through the upper blade body; and alever having a pair of supporting arms; the upper end portion of thesupporting shaft being inserted on the upper blade body to a bearingrecess defined between the supporting arms of the lever; a firstsupporting section provided in the supporting arms; and a secondsupporting section provided at the upper end portion of the supportingshaft; the first and second supporting sections being linked to eachother; wherein the upper cutting edge and the lower cutting edge arebrought into press contact with each other by pressing the upper bladebody with the lever against resilience of the upper and lower bladebodies. In this nail clipper, the first supporting section of the leveris a pair of bosses protruding from the supporting arms respectively tooppose each other in the bearing recess of the lever; whereas the secondsupporting section of the supporting shaft is a groove formedcontinuously fully along the circumference thereof, with which thebosses are engaged. Each groove has a mouth portion through which thebosses are engaged and disengaged and a guiding portion capable ofpivotally supporting the bosses.

The nail clipper according to another embodiment contains an upper bladebody having an upper cutting edge; a lower blade body having a lowercutting edge opposed to the upper cutting edge; a supporting shaftinserted to the blade bodies near the cutting edges respectively, alower end portion of the supporting shaft being engaged with the lowerblade body to be locked therewith, while an upper end portion of thesupporting shaft protrudes upward through the upper blade body; a firstsupporting section provided in a lever; and a second supporting sectionprovided at the upper end portion of the supporting shaft, the first andsecond supporting sections being linked to each other; wherein the uppercutting edge and the lower cutting edge are brought into press contactwith each other by pressing the upper blade body with the lever againstresilience of the upper and lower blade bodies. In this nail clipper,the supporting shaft is molded with a synthetic resin material.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1(a) is a front view of the nail clipper according to a firstembodiment, showing a state where the nail clipper is at rest; FIG. 1(b)is a perspective view showing the supporting shaft of the nail clipper;and FIG. 1(c) is a perspective view showing the lever of the nailclipper;

FIG. 2(a) is a front view of the supporting shaft of the nail clipper;FIG. 2(b) is a left side view of the supporting shaft shown in FIG.2(a); and FIG. 2(c) is a bottom view of the supporting shaft shown inFIG. 2(a);

FIG. 3(a) is a cross-sectional view taken along the line 3 a— 3 a inFIG. 2(a); FIG. 3(b) is a cross-sectional view taken along the line 3 b—3 b in FIG. 2(a); and FIG. 3(c) is a cross-sectional view taken alongthe line 3 c— 3 c in FIG. 2(a);

FIG. 4(a) is a partial plan view of the lever of the nail clipper; andFIG. 4(b) is a left side view of the lever shown in FIG. 4(a);

FIGS. 5(a), 5(b) and 5(c) are partial cross-sectional views showingprocess steps of engaging the pair of bosses of the lever with thegrooves of the supporting shaft;

FIG. 6(a) is a cross-sectional view taken along the line 6 a— 6 a inFIG. 5(b); and FIG. 6(b) is a cross-sectional view taken along the line6 b— 6 b in FIG. 5(c);

FIG. 7(a) is a front view of the nail clipper according to the firstembodiment showing a state where the nail clipper is ready for use; andFIG. 7(b) is a front view thereof showing a state where the nail clipperis in action;

FIG. 8(a) is a front view showing the support shaft in the nail clipperaccording to another embodiment; FIG. 8(b) is a left side view of thesupporting shaft shown in FIG. 8(a); FIG. 8(c) is a cross-sectional viewtaken along the liner 8 c—8 c in FIG. 8(a); and FIG. 8(d) is across-sectional view taken along the line 8 d— 8 d in FIG. 8(a);

FIG. 9(a) is a cross-sectional view showing a transient step of formingbosses in the lever of the nail clipper according to another embodiment;and FIG. 9(b) is a cross-sectional view showing the bosses; and

FIG. 10(a) is a front view showing the groove of the supporting shaft inthe nail clipper according to another embodiment; and FIG. 10(b) is across-sectional view taken along the line 10 b— 10 b in FIG. 10(a).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The nail clipper according to a first embodiment of the presentinvention will be described below referring to FIGS. 1 to 7.

Scheme of Nail Clipper

As shown in FIG. 1(a), the nail clipper has an upper blade body 1 and alower blade body 2 each having a plate form, which are fixed to eachother at proximal portions 1 a and 2 a. The upper blade body 1 and thelower blade body 2 have resilience and can be moved closer to and awayfrom each other. The upper blade body 1 and the lower blade body 2 havecutting edges 3 and 4 formed at the distal ends thereof respectively tooppose each other. The upper cutting edge 3 and the lower cutting edge 4are normally spaced away from each other by the resilience of the bladebodies 1 and 2. As shown in FIGS. 5(a), 5(b) and 5(c), circular bearingholes 5 and 6 are defined through the upper blade body 1 and the lowerblade body 2, and they are located near the cutting edges 3 and 4,respectively.

A supporting shaft 7 shown in FIG. 1(b) penetrates the upper blade body1 through the bearing hole 5 thereof and the lower blade body 2 throughthe bearing hole 6 thereof. This supporting shaft 7 contains alarge-diameter head 8 formed at the lower end thereof and asmall-diameter shank 10 extended from the head 8 upward through a step9. The head 8 is locked by the rim of the bearing hole 6 on the lowerside of the lower blade body 2. An upper end portion 11 of the shank 10protrudes through the bearing hole 5 to the upper side of the upperblade body 1.

A lever 12 shown in FIG. 1(c) is placed on the upper side of the upperblade body 1. The lever 12 is forked at the distal portion to form apair of supporting arms 13 and also a bearing recess 14 between thesetwo supporting arms 13. The upper end portion 11 of the supporting shaft7 is inserted to this bearing recess 14. Each supporting arm 13 of thelever 12 and the upper end portion 11 of the supporting shaft 7 arelinked to each other in a supporting section S.

Materials of Supporting Shaft 7 and Lever 12

Both the supporting shaft 7 and the lever 12 are integrally moldedrespectively with a synthetic resin material. The synthetic resinmaterial is based on polyamide, polypropylene or aromatic nylon and cancontain a predetermined filler. As the filler, a glass fiber, a mineralfiber or a carbon fiber can be used singly, or a combination of at leasttwo of the glass fiber, mineral fiber and carbon fiber may be used.Provided that the content (wt %) of such fillers is α, the value α isdefined in this embodiment as 15%≦α≦65%. However, it is preferably40%≦α≦60%.

The following characteristics can be obtained by utilizing suchsynthetic resins.

(1) Synthetic resins have high strength and high rigidity after wettingor at high temperatures, high impact strength and high elongation atbreak as rigid materials and excellent fatigue strength, so that theshaft 7 and the lever 12 come to have high strength and rigidity.

(2) Synthetic resins have good fluidity and provide good appearance,since they can be subjected to injection molding at a mold temperatureof 80 to 110° C. and since dies, screws and cylinders do not wear much;and

(3) Synthetic resins do not wear much when they are brought into contactwith metallic materials to improve wear resistance of the shaft 7 and ofthe lever 12.

Linking Structure of Supporting Shaft 7 and Lever 12

As shown in FIG. 1(c), in the bearing recess 14 of the lever 12, a boss15 (supporting section S) is formed on each supporting arm 13 such thatthe boss formed on one supporting arm 13 opposes the counterpart formedon the other supporting arm 13. Both the head 8 and the shank 10 of thesupporting shaft 7 are formed to have circular cross sectionsrespectively. The shank 10 has on each side of the circumference thereofa pair of grooves 16 (supporting section S) at 180° intervals to opposethe bosses 15 respectively, and the bosses 15 are engaged with theopposing grooves 16 respectively.

As shown in FIGS. 1(b), 2(a) to 2(c) and FIGS. 3(a) to 3(c), each groove16 contains a mouth portion 17 engageable with and disengageable fromthe boss 15, a guiding portion 18 capable of pivotally supporting theboss 15, and a connecting portion 19 connecting the mouth portion 17 andthe guiding portion 18 to each other. Each groove 16 has a pair ofopposing side wall surfaces 20 in the mouth portion 17, connectingportion 19 and guiding portion 18; a bottom surface 21 connecting thepair of side wall surfaces 20 to each other in the mouth portion 17,connecting portion 19 and guiding portion 18; and an opening 22 opposingthe bottom surface 21. The pair of grooves 16 are separated from eachother by a common bottom plate 23 throughout the mouth portion 17,connecting portion 19 and guiding portion 18. The bottom surfaces 21 ofthe grooves 16 are located on each side of the bottom plate 23 in themouth portion 17, connecting portion 19 and guiding portion 18.

The center line between the pair of side wall surfaces 20 in each groove16 extends throughout the mouth portion 17, connecting portion 19 andguiding portion 18. The center line contains a first portion 17 arunning through the mouth portion 17, a second portion 19 a runningthrough the connecting portion 19 and a third portion 18 a runningthrough the guiding portion 18. The first portion 17 a extends from themouth portion 17 to the connecting portion 19 orthogonally to the axialdirection 7 a of the supporting shaft 7. The third portion 18 a extendsfrom the connecting portion 19 to the guiding portion 18 along the axialdirection 7 a of the supporting shaft 7. The second portion 19 a isarcuated to connect the first portion 17 a and the third portion 18 a toeach other.

The pair of side wall surfaces 20 in each groove 16 are inclined to beaway from each other toward the opening 22. Thus, the distance W betweenthe side wall surfaces 20 in each groove 16 is designed to be greater onthe opening (22) side than on the bottom surface (21) side.

Provided that the thickness of the bottom plate 23 or the distancebetween the bottom surfaces 21 of the grooves 16 is T; the distancebetween the opening 22 of the grooves 16 or the outside diameter of theshank 10 of the supporting shaft 7 is D₁₀; and that the value T(thickness)/D₁₀ (outside diameter) is A, the value A is set within therange of 0≦A≦0.5. More preferably, the value A is set within the rangeof 0.2≦A≦0.4. In each groove 16 of this embodiment, the bottom plate 23is formed throughout the mouth portion 17, connecting portion 19 andguiding portion 18. However, for example, the bottom plate 23 may beformed in the mouth portion 17 and a part of the connecting portion 19,and the bottom plate 23 may be omitted in the rest of the connectingportion 19 and in the guiding portion 18 to allow the grooves 16 tocommunicate with each other. In the case where the bottom plate 23 isomitted, T=0, and hence A=0.

Provided that the distance between the side wall surfaces 20 in theguiding portion 18 of each groove 16 and the outside diameter of theshank 10 of the supporting shaft 7 are W and D₁₀ respectively and thatthe value W (distance)/D₁₀ (outside diameter) is B, the value B is setwithin the range of 0.15≦B≦0.8 in this embodiment. The value B is morepreferably set within the range of 0.4≦B≦0.7.

In the supporting shaft 7, the outside diameter D₈ of the head 8 isdesigned to be greater than the outside diameter D₁₀ of the shank 10.Provided that the length of the head 8 along the axial direction 7 a andthe length of the shank 10 along the axial direction 7 a are H and Lrespectively and that the value H (width)/L (length) is C, the value Cis set within the range of 0.05≦C≦0.3 in this embodiment. The value C ismore preferably set within the range of 0.1≦C≦0.2.

Further, in the supporting shaft 7, the step 9 present between the head8 and the shank 10 has a reinforcing portion 24 having an arcuate crosssection formed fully along the outer circumference. Provided that theradius of the reinforcing portion 24 is r, the value r is set within therange of 0.1 mm≦r≦3 mm. The value r is more preferably set within therange of 0.2 mm≦r≦1.5 mm.

Referring to the thickness T of the bottom plate 23 present between thegrooves 16, each bottom surface 21 is sloped or stepped from the mouthportion 17 toward the guiding portion 18 so that the thickness T isgreater on the mouth portion (17) side than on the guiding portion (18)side. In other words, each groove 16 is designed to have such a depth asis slightly shallower on the mouth portion (17) side than on the guidingportion (18) side. Meanwhile, the distance W between the side wallsurfaces 20 in each groove 16 is designed to be greater on the mouthportion (17) side than on the connecting portion (19) side or thepivotal guiding portion (18) side. Further, the supporting shaft 7 has alocking pin hole 25 formed in the head 8 thereof.

Next, the bosses 15 shown in FIG. 1(c) and FIGS. 4(a) and 4(b) will bedescribed. Each boss 15 has a peripheral surface 28 formed to extendfrom a proximal portion 26 to a distal portion 27 thereof, and an endface 29 provided at the distal portion 27. In each boss 15, the crosssection taken orthogonal to the axial direction 15 a has a circularshape. The peripheral surface 28 is tilted with respect to the axialdirection 15 a. The peripheral surface 28 of each boss 15 is designed tohave an outside diameter D₂₆ at the proximal portion 26, which isgreater than the outside diameter D₂₇ of the same at the distal portion27. Thus, a cross-sectional area of each boss 15 taken orthogonal to theaxial direction 15 a reduces gradually from the proximal portion (26)side toward the distal portion (27) side.

In each boss 15, provided that the outside diameter of the peripheralsurface 28 at the proximal portion 26 and the length from the proximalportion 26 to the distal portion 27 in the axial direction 15 a are D₂₆and M respectively, and that the value D₂₆ (outside diameter)/M (length)is E, the value E is set within the range of 1≦E≦3 in this embodiment.The value E is more preferably set within the range of 1.5≦E≦2.5.

In the bosses 15, provided that the sum of the length M in the axialdirection 15 a from the proximal portion 26 to the distal portion 27 inone boss 15 and the length M in the axial direction 15 a from theproximal portion 26 to the distal portion 27 in the other boss 15 is N(N=M+M), and the dimension of a clearance 30 secured between the distalportions 27 of the bosses 15 (i.e., the clearance between the end faces29) is P, and that the value N (sum of lengths)/P (clearance) is F, thevalue F is set within the range of 1≦F≦3 in this embodiment. The value Fis more preferably set within the range of 1.3≦F≦2.3.

Next, the procedures of coupling the bosses 15 with the grooves 16respectively and supporting state between them will be described.

As shown in FIG. 5(a), in the state where the supporting shaft 7penetrates through the upper and lower blade bodies 1 and 2, a lockingpin (not shown) is inserted to the locking pin hole 25 formed at thehead 8 of the supporting shaft 7 to achieve positioning of thesupporting shaft 7, and also the upper blade body 1 is pushed down sothat the cutting edges 3 and 4 of the blade bodies 1 and 2 approach eachother. In this state, the supporting arms 13 of the lever 12 are appliedonto the upper side of the upper blade body 1, and the bosses 15 of thesupporting arms 13 are moved, on the upper side of the upper blade body1, toward the grooves 16 formed at the upper end portion 11 of the shank10 in the supporting shaft 7.

Next, as shown in FIGS. 5(b) and 6(a), each boss 15 is engaged with themouth portion 17 of the opposed groove 16 while the upper end portion 11of the shank 10 is inserted to the bearing recess 14 defined between thesupporting arms 13. At the initial stage of engagement, each boss 15approaches the side wall surfaces 20 of the groove 16 such that theperipheral surface 28 of the boss 15 slides along the side wall surfaces20 of the groove 16 and that the end face 29 of the boss 15 slides alongthe bottom surface 21 of the groove 16.

Further, as shown in FIGS. 5(c) and 6(b), each boss 15 is slipped fromthe mouth portion 17 of the groove 16 into the guiding portion 18through the connecting portion 19 in each groove. In the state where theboss 15 is fully engaged with the groove 16, the boss 15 is brought intopressure contact with the side wall surfaces 20 of the guiding portion18 under the resilience of the upper and lower blade bodies 1 and 2 soas to regulate the boss 15 not to shift toward the connecting portion 19of the groove 16.

Example of How the Nail Clipper is Used

In the state where the nail clipper is at rest as shown in FIG. 1(a),the lever 12 is turned over to rest on the upper side of the upper bladebody 1, and the upper and lower blade bodies 1 and 2 are spacedvertically from each other under the resilience thereof. In this state,the resilience of the upper blade body 1 is borne by the bosses 15 andthe grooves 16 formed in the shank 10 of the supporting shaft 7 throughthe supporting arms 13 of the lever 12; whereas the resilience of thelower blade body 2 is borne by the head 8 of the supporting shaft 7,maintaining the upper cutting edge 3 and the lower cutting edge 4 to bespaced away from each other.

Next, the lever 12 is pivoted on the upper side of the upper blade body1 by 180° together with the supporting shaft 7 and then inverted to bepositioned over the upper blade body 1 so as to form an upward slopewith respect to the blade body 1, as shown in FIG. 7(a) illustrating thestate where the nail clipper is ready for use. Then, the upper bladebody 1 is pressed with the lever 12 against the resilience of the upperand lower blade bodies 1 and 2, and the upper cutting edge 3 and thelower cutting edge 4 are brought closer and abutted against each other,as shown in FIG. 7(b) illustrating the state where the nail clipper isin action.

In any of the states described above, the bosses 15 of the lever 12 movewithin the guiding portions 18 of the respective grooves 16 defined inthe supporting shaft 7 following the movement of the lever 12.

Other Embodiments

Another Embodiment Shown in FIG. 8

In the first embodiment shown in FIGS. 2(a) and 2(b), each groove 16 hasthe mouth portion 17 only on one side of the axial line 7 a of thesupporting shaft 7. However, in the embodiment shown in FIGS. 8(a) and8(b), each groove 16 has a pair of mouth portions 17 on each side of theaxial line 7 a of the supporting shaft 7.

Another Embodiment Shown in FIG. 9

In the first embodiment shown in FIG. 1(c), the entire lever 12including the bosses 15 is molded with a synthetic resin material.However, in the embodiment shown in FIG. 9(a), the main body of thelever 12 is molded with a synthetic resin material, and a metallicboss-forming material 31 is inserted to the supporting arms 13 to beintegrated with the lever 12, and then the boss-forming material 31 iscut to form a pair of bosses 15.

Another Embodiment Shown in FIG. 10

In the first embodiment, the grooves 16 are defined on the periphery ofthe shank 10 of the supporting shaft 7 to oppose diametrically eachother. In place of this constitution, a groove 16 is formed fully alongthe circumference of the shank 10 of the supporting shaft 7. This groove16 has an upper edge and a lower edge, and the upper edge has a wavyconvexoconcavity 32. Further, a guiding portion 18 also serving as amouth portion 17 is provided between each concavity 32 a of the upperedge and the lower edge. The boss 15 in each supporting arm 13 of thelever 12 is introduced through this mouth portion 17 into the guidingportion 18.

Although not illustrated, the groove formed fully along thecircumference of the shank 10 of the supporting shaft 7 may have thefollowing constitution. A crosswise groove is formed on the shank 10 ofthe supporting shaft 7 in the circumferential direction. While thecrosswise groove has an upper edge and a lower edge intersecting withthe axial direction 7 a, a plurality of vertical grooves are formed toextend parallelwise from the upper edge in the axial direction. Thecrosswise groove serves both as a mouth portion and as a connectingportion. Each vertical groove serves both as a connecting portion and asa guiding portion. The bosses 15 in the supporting arms 13 of the lever12 are introduced from the mouth portion into the guiding portionsthrough the connecting portions, respectively.

In any of the above embodiments, the supporting shaft 7 is provided witha groove or grooves 16, whereas each supporting arm 13 of the lever 12is provided with a boss 15. Although not illustrated, in place of thisconfiguration, a boss may be formed on the supporting shaft 7, and agroove may be formed on each supporting arm 13 of the lever 12.

Although not shown, the configuration of the boss 15 in each supportingarm 13 of the lever 12 may be modified. While the bosses 15 in theforegoing embodiments have a truncated cone shape, they may have, forexample, a columnar or semispherical shape. Further, each boss 15 mayhave an elliptical cross section in place of the circular cross section.

1. In a nail clipper containing an upper blade body having an uppercutting edge; a lower blade body having a lower cutting edge opposed tothe upper cutting edge; a supporting shaft inserted to the blade bodiesnear the cutting edges respectively, a lower end portion of thesupporting shaft being engaged with the lower blade body, while an upperend portion of the supporting shaft protruding upward through the upperblade body; a lever having a pair of supporting arms; the upper endportion of the supporting shaft being inserted on the upper blade bodyto a bearing recess defined between the supporting arms of the lever; afirst supporting section provided in the supporting arms; and a secondsupporting section provided at the upper end portion of the supportingshaft; the first and second supporting sections being linked to eachother; the upper cutting edge and the lower cutting edge being broughtinto press contact with each other by pressing the upper blade body withthe lever against resilience of the upper and lower blade bodies,wherein the improvement which comprises: a pair of bosses opposing eachother, formed as one of the group consisting of the first supportingsection of the lever and as the second supporting section of thesupporting shaft, and a pair of grooves formed as the other of the groupconsisting of the first supporting section of the lever and the secondsupporting section of the supporting shaft, with which the bosses areengaged respectively; the grooves each having a mouth portion throughwhich the boss is engaged and disengaged, a guiding portion capable ofpivotally supporting the boss, and a connecting portion connecting themouth portion and the guiding portion to each other; the groove having apair of side wall surfaces opposing each other in the mouth portion,connecting portion, and guiding portion, and also a bottom surfaceconnecting the side wall surfaces to each other.
 2. The nail clipperaccording to claim 1, wherein the bosses formed as one supportingsection are provided in the supporting arms respectively to oppose eachother in the bearing recess of the lever, whereas the grooves formed asthe other supporting section are defined on the circumference of thesupporting shaft to oppose the bosses respectively.
 3. The nail clipperaccording to claim 2, wherein the grooves defined in the supportingshaft are separated from each other by a bottom plate throughout themouth portion, connecting portion, and guiding portion, and each groovehas a bottom surface formed on the bottom plate throughout the mouthportion, connecting portion, and guiding portion.
 4. The nail clipperaccording to claim 3, wherein either the distance between the bottomsurfaces of the grooves or the thickness of the bottom plate is designedto be greater on the mouth portion side than on the guiding portionside.
 5. The nail clipper according the claim 3, wherein provided that Trepresents the distance between the bottom surfaces of the grooves orthe thickness of the bottom plate; D₁₀ represents the outside diameterof the supporting shaft; and A represents a value T (thickness)/D₁₀(outside diameter), the value A is set within the range of 0≦A≦0.5. 6.The nail clipper according to claim 2, wherein a central line betweenthe side wall surfaces in each groove of the supporting shaft extendsthrough the mouth portion, connecting portion, and guiding portion; andcontains a first portion passing through the mouth portion, a secondportion passing through the connecting portion, and a third portionpassing through the guiding portion.
 7. The nail clipper according toclaim 6, wherein the second portion of the central line contains aportion extending from the mouth portion to the connecting portionorthogonal to the axial direction of the supporting shaft, and a portionextending from the connecting portion to the guiding portion in theaxial direction of the supporting shaft.
 8. The nail clipper accordingto claim 7, provided that W represents the distance between the sidewail surfaces in the guiding portion of each groove; D₁₀ represents theoutside diameter of the supporting shaft; and B represents a value W(distance)/D₁₀ (outside diameter), the value B is set within the rangeof 0.15 ≦B≦0.8.
 9. The nail clipper according to claim 2, wherein thedistance W between the side wall surfaces of each groove is designed tobe greater on the mouth portion side than on the connecting portion sideor on the guiding portion side.
 10. The nail clipper according to claim2, wherein each boss has a proximal portion, a distal portion, aperipheral surface, and an end face at the distal portion; the boss hasa cross-sectional area orthogonal to the axial direction of the boss,which cross-sectional area is designed to be greater on the proximalportion than on the distal portion.
 11. The nail clipper according toclaim 10, wherein the cross section of each boss orthogonal to the axialdirection of the boss has a circular shape, and the outside diameter ofthe cross section of the boss reduces gradually from the proximalportion toward the distal portion.
 12. The nail clipper according toclaim 11, wherein provided that D₂₆ represents the outside diameter ofthe cross section of the proximal portion of each boss; M represents theaxial length of the boss from the proximal portion to the distalportion; and E represents a value D₂₆ (outside diameter)/M (length), thevalue E is set within the range of1≦E≦3.
 13. The nail clipper accordingto claim 11, wherein provided that N represents the sum of the lengths Min the pair of bosses; P represents the distance between the end facesof the bosses; and F represents a value N (sum of lengths)/P (distance),the value F is set within the range of 1≦F≦3.
 14. The nail clipperaccording to claim 2, wherein the side wall surfaces in each groove ofthe supporting shaft are provided adjacent to each other so that theyare substantially in contact with the peripheral surface of the boss ofthe lever.
 15. The nail clipper according to claim 14, wherein thedistance W between the side wall surfaces in each groove of thesupporting shaft is designed to be greater on the opening side than onthe bottom surface side such that the distance W becomes smaller towardthe deeper side of the groove.
 16. The nail clipper according to claim2, wherein the supporting shaft has a head located at the lower endthereof and a shank formed contiguous to the head through a step; thehead has an outside diameter D₈, which is greater than the outsidediameter D₁₀ of the shank; and provided that H represents the axiallength of the head, L represents the axial length of the shank, and Crepresents a value H (width)/L (length), the value C is set within therange of 0.05≦C ≦0.3.
 17. The nail clipper according to claim 16,wherein the step formed between the head and the shank in the supportingshaft is provided with a reinforcing portion having an arcuate crosssection formed fully along the periphery thereof, and provided that rrepresents the radius in a cross sectional profile of the reinforcingportion, the value r is set within the range of 0.1 mm ≦r≦3 mm.
 18. Thenail clipper according to claim 2, wherein, when the boss is supportedin the guiding portion of the groove, the boss is brought into presscontact with the side wall surfaces of the guiding portion underresilience of the upper and lower blade bodies so that the boss does notshift toward the connecting portion of the groove.
 19. The nail clipperaccording to claim 2, wherein each groove has a pair of mouth portionsdefined on each side of the axial line of the supporting shaft.
 20. Thenail clipper according to claim 2, wherein the bosses on the supportingarms of the lever are made of a metal, and in the case where the leveris molded with a synthetic resin material, the bosses are formedintegrally with the lever using an insert.
 21. The nail clipperaccording to claim 2, wherein the supporting shaft has at the lower enda locking pin hole.
 22. In a nail clipper containing an upper blade bodyhaving an upper cutting edge; a lower blade body having a lower cuttingedge opposed to the upper cutting edge; a supporting shaft inserted tothe blade bodies near the cutting edges respectively, a lower endportion of the supporting shaft being engaged with the lower blade bodyto be locked therewith, while an upper end portion of the supportingshaft protrudes upward through the upper blade body; and a lever havinga pair of supporting arms; the upper end portion of the supporting shaftbeing inserted on the upper blade body to a bearing recess definedbetween the supporting arms of the lever; a first supporting sectionprovided in the supporting arms; and a second supporting sectionprovided at the upper end portion of the supporting shaft; the first andsecond supporting sections being linked to each other; the upper cuttingedge and the lower cutting edge being brought into press contact witheach other by pressing the upper blade body with the lever againstresilience of the upper and lower blade bodies, wherein the improvementwhich comprises: a pair of bosses protruding as the first supportingsection of the lever from the supporting arms respectively to opposeeach other in the bearing recess of the lever; and a groove, with whichthe bosses are engaged, formed as the second supporting section of thesupporting shaft on the circumference thereof; the groove being formedcontinuously fully along the circumference of the supporting shaft andhaving a mouth portion through which the bosses are engaged anddisengaged and a guiding portion capable of pivotally supporting thebosses.